package saimaCode;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;


/**
 * Created by lxy_920912 on 30/03/2017.
 */
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double n = scanner.nextDouble();

        String str = scanner.nextLine();
        System.out.println("str:"+str);
        int m = scanner.nextInt();
        List<Double> result = new ArrayList<>();
        result.add(n);
        for(int i = 1;i < m;i++){
            n = Math.sqrt(n);
            result.add(n);
        }
        double sum = 0;
        for(int i = 0;i < m;i++){
            sum = sum + result.get(i);
        }
        DecimalFormat df = new DecimalFormat("#.00");

        System.out.println(df.format(sum));
    }
}
